Turn Signal Indicator Actuation, Function - GF82.10-P-3008KJ

MODEL 453.0/3/4 

Function requirements, general 

• No overvoltage or undervoltage

Turn signal light actuation, general 

The turn signal light actuation consists of all functions for output of the turn signal, various warnings and feedback.

The master control unit for all flashing functions is the front SAM control unit (N10/10).

The respective active function is visually displayed to the driver via the left turn signal light indicator lamp (A1e1) or the right indicator light indicator lamp (A1 e2). For acoustic feedback, the instrument cluster (A1) actuates the turn signal lights, acoustic function check (A1 h2). If a turn signal light or turn signal lamp fails, the frequencies of the turn signal indicator lamps and the acoustic function check are doubled.

The turn signal light actuation encompasses the following partial functions:

• Function sequence for turn indicators 
• Function sequence, hazard warning flashing Additional function requirements for turn signaling 
• Engine running (except model 453.091/391/491)
• Drivetrain operational ("READY" status) (model 453.091/391/491)

Function sequence for turn indicators 

The turn signaling function encompasses the following subfunctions:

• Function sequence, left turn signaling 
• Function sequence, right turn signaling 
• Function sequence, one-touch turn signaling 

Function sequence, left turn signaling 

The left turn signal function is requested by pushing the combination switch (S4) downward.

The center SAM control unit reads in the switch position of the combination switch directly and actuates the left turn signal lamp (E6/1), the left additional turn signal lamp (E22/1) and the left rear turn signal light (E3e1) in a pulsed rhythm.

By way of a visual check, the center SAM control unit places the "left turn signal" (flasher frequency) requests on the interior CAN (CAN-B). The instrument cluster receives the flasher frequency and actuates the left turn signal indicator lamp and the turn signal light acoustic function check.

Function sequence, right turn signaling 

The right turn signal function is requested by pushing the combination switch upward.

The center SAM control unit reads in the switch position of the combination switch directly and actuates the right turn signal lamp (E6/2), the right additional turn signal lamp (E22/2) and the right rear turn signal light (E4e1) in a pulsed rhythm.

By way of an visual check, the center SAM control unit places the "right turn signal" (flasher frequency) requests on the interior CAN (CAN-B).

The instrument cluster receives the flasher frequency and actuates the right turn signal indicator lamp and the turn signal light acoustic function check.

Function sequence, touch turn signaling (quick flashing) 

With regard to signal flow, the function sequence of the touch turn signal function corresponds to that of the left turn signal and right turn signal functions. The difference is in the triggering and ending of the turn signal procedure.

To trigger the touch turn signaling function, the combination switch must only be pressed briefly in the desired turn signal direction until the actuating point is reached.

As a result, 3 flashing cycles are output or triggered by the center SAM control unit.

The touch turn signaling function is canceled by actuating the combination switch in the opposite direction.

Function sequence, hazard warning flashing 

The hazard warning flasher function sequence is the same as that for turn signaling with regard to the signal flow.

However, all the turn signal lights and turn signal lamps on the vehicle are actuated synchronously.

The hazard warning flashing function encompasses the following subfunctions:

• Function sequence for hazard warning flashing, manual 
• Function sequence for hazard warning flasher after emergency braking 
• Function sequence for hazard warning flasher when airbag deployed 
• Function sequence, feedback from locking/unlocking of central locking (CL) 

Function sequence for hazard warning flashing, manual 

The manual hazard warning flasher function is activated by pressing the hazard warning system switch (S6/1s1).

The center SAM control unit reads in the status of the hazard warning system switch directly and then actuates all turn signal lights and turn signal lamps on the vehicle synchronously. By way of a visual check, the center SAM control unit places a flasher frequency on the interior CAN; this is received by the instrument cluster which actuates visually the indicator lamp turn signal light and acoustically the acoustic function check.

The hazard warning system indicator lamp (S6/1e4) in the hazard warning system switch is also directly actuated by the center SAM control unit.

The hazard warning flasher function is overridden by triggering the turn signaling function. If the combination switch is pressed in one direction while the hazard warning flasher is flashing, only the turn signal lamps and turn signal lights on the relevant side will flash.

Additional function requirements for hazard warning flasher after emergency braking 

• Vehicle is braked sharply from a speed of more than 70 km/h and comes to a standstill.

Function sequence for hazard warning flasher after emergency braking 

In the case of emergency braking followed by a standstill of the vehicle, the Electronic Stability Program control unit (N30/4) sends the "Hazard warning system for emergency braking" request via interior CAN to the center SAM control unit.

The center SAM control unit then activates the hazard warning flasher function.

The hazard warning flasher is deactivated after emergency braking by pressing the hazard warning system switch or upon exceeding a speed of v = 10 km/h.

Additional function requirements for hazard warning flasher when airbag deployed 

• Deceleration a > 4 g

Function sequence for hazard warning flasher when airbag deployed 

If the airbag is deployed, the crash signal is transmitted by the supplemental restraint system (N2/10) control unit via the interior CAN to the center SAM control unit.

The center SAM control unit then triggers the hazard warning flasher function.

Function sequence, feedback from locking/unlocking of central locking (CL) 

If the center SAM control unit receives the "Unlock central locking" or "Lock central locking" request from the transmitter key, it actuates all turn signal lamps and turn signal lights on the vehicle.

The center SAM control unit activates the hazard warning flashing function for one flasher cycle when the central locking system is unlocked, and for two flasher cycles when the central locking system is locked.

The detailed description of this function can be found in the separate "Central locking (CL [ZV]), function" description.

	Electrical function schematic, turn signal light actuation		PE82.10-P-2057-97BBA
	Overview of exterior lights system components		GF82.10-P-9998KJ